That's my system:

Operating System: KDE neon 5.23
KDE Plasma Version: 5.23.4
KDE Frameworks Version: 5.89.0
Qt Version: 5.15.3

I've noticed that I cant use the Alt + ` shortcut to alternate into windows of the same app.

So I went to check if the shortcut was correctly assigned and it was.

I've tried to change it to another set of keys and it works, but when I try to set it back to the default, this happens:



I'm entering Alt + ` but it looks like it's not what KDE gets from the keys combination.

I'm using the English ( US ) Layout with the English ( Us, alt. intl.) variant, and that seems to be the problem.

If I change it to the English ( US ) Default layout it works.